How common is it for a new breaker to be bad or weak?
During framing, I temped up 2 circuits, and one of them would blow pretty easily. But with a compressor, and a couple saws, etc running, and the confusion over which cord is on which circuit, I didn’t think much of it.
I just finished up the last 2 circuits in the garage, and went hunting around and found “I Think” those 2 original temp breakers.
Long story short, one of the circuits in the garage blows the breaker intermittently with no load. I have preformed a quick and dirty investigation, and found no trouble so far, but I certainly can’t rule out a wiring problem. But I also think one of those breakers is suspect, but wasn’t sure how often a breaker actually went bad.
Square D QO series 20 amp.
A medium to large guy named Alan, not an ambiguous female….
NOT that there is anything wrong with that.
Replies
I'd just replace the breaker and see if the problem continues. Bad breakers aren't that unusual, and if you did reuse the compressor breaker it may have been worn out from tripping.
Have installed and used hundreds of QO breakers, probably the best, have never had a 'bad' one, esp one that would trip on 'no load'.
Did see a GE breaker trip once on 'no load' --- that turned out to be a nail thru the romex. Random tripping every few weeks, probably due to thermal or moisture difference movement of the nail just grazing the wire.
Check the fingers that snap over the busbar - if discolored due to heat, they probably got bent and the heat due to poor contact (under load) is causing a trip; but, that would not happen under no load as you describe.
A hipot test of the suspect circuit is in order, you probably do have something amiss with your wiring. Unlikely a QO would 'wear out' just from a few trips due to a compressor.
CHECK YOUR WIRING. If you don't have a hipot tester, replace that whole wire run if you do not find the trouble, esp if a 'new breaker' is also 'bad'.
I'd pull the breaker and replace it, they do get weak after they trip a few times.
I would also, at least stick a VOM on it and see whether you have a short. If you get anything below infinity for a resistance something is wrong. If you have a megger it would be preferred, but it is kind of a specialized tool most guys don't own. You can pick up a decent VOM for less than fifty dollars.
I would check the cords or the line coming from the temp circuits. If the breaker is tripping with no load on it, it could be something as easy as just a whole in the line that's allowing the wires to touch each other.
On the jobs I've framed, the cords would get run over by cars and other equiptment (lulls). Romex could easily get damaged if it happened to get run over while it was laying on rocks or something sharp. Of course our temp outlets were GFCI's and every so often we would just have to hunt down a short in the wire and tape it back up.
Of course our temp outlets were GFCI's and every so often we would just have to hunt down a short in the wire and tape it back up.
Course that is OSHA approved tape, isn't it? :-)
Dave
Thanks for the info guys.I will check the circuit over if it still trips a new breaker.I've got a couple multi-meters. This circuit runs uninterupted from one corner of the house to the garage. so I will pull the first outlet and test from there. If all is well there I can be sure that it is something downstream that I have screwed up, but so far that only amounts to a couple outlets and an exterior light. If it's the other way, I have some unpleasant fishing to do to get a new wire to the garage, but hey what's the fun in doing somwething right the first time? :)A medium to large guy named Alan, not an ambiguous female....
NOT that there is anything wrong with that.
Doh! I nicked the hotwire on the bottom wire clamp in one of the outlet boxes.Just barely nicked, but the second round of testing with my highly complicated extension cord with led light in the female end, worked like a charm. I like to get rough with the plug ins for just that reason, and the fireworks made it an easy problem to find.Anyway you all can rest easier now that my verys simple problem is resolved. :DA medium to large guy named Alan, not an ambiguous female....
NOT that there is anything wrong with that.
should be pretty easy to swap it with another breaker, see whether the problem follows the breaker or the circuit.
While the breaker is out, do inspect the bus rails for discoloration suggesting a bad connection and overheating.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin